轴向压缩悬臂梁压电双晶片动静态特性研究

Static and Dynamic Study on Static and Dynamic Characteristics of Axial Compressed Cantilever Piezoelectric Bimorph

研究施加轴向压缩力于悬臂梁压电双晶片端部以增大端部输出位移和力的问题,对其进行了有限元分析,并推导了弹性力学解析解及模态方程,得到了符合程度较好的结果。研究结果表明,在120V电压及5.5N轴向力作用下,端部阻塞力达0.25N,输出位移较原来增大3倍以上(达5mm),而一阶特征频率随轴向力增大而加速减小。当轴向力达到一阶临界屈曲时,一阶特征频率趋于0,但当轴向力取一阶屈曲力的70%时,其1阶固有频率仍有45Hz,相较于普通伺服舵机有较大的优势,可有效提高微小型飞行器的操稳性。

The method of increasing the end output displacement and force by applying axial compressive force to the cantilever piezoelectric bimorph end was studied in this paper. The FEM analysis was carried out, the elastic an- alytical solution and the modal equations were deduced, demonstrating a good coincidence between them. The result shows that under 120 V and 5.5 N axial forces, a 0.25 N ending block force and a 5 mm ending free displacement which is 3 times bigger than the original bimorph are obtained. However, the first nature frequency displays acceler- ated decreasing as the axial force increasing, When the axial force reaching the first-order buckling load, the first na ture frequency tends to be 0, and when it is 70% of the first-order buckling force, the nature frequency still can be 45 Hz, which is a great advantage over the conventional servo actuator. Therefore, this actuator can improve the stability and controllability of micro air vehicle （MAV） effectively.